Related Experiment Videos
Update of newborn screening and therapy for congenital hypothyroidism
, Susan R Rose,
Insights
Early diagnosis and treatment of congenital hypothyroidism (CH) in newborns are crucial for normal cognitive development. Prompt thyroid hormone therapy, guided by thyroid-stimulating hormone levels, significantly improves long-term outcomes.
Area of Science:
- Pediatrics
- Endocrinology
- Neonatology
Background:
- Congenital hypothyroidism (CH) left untreated can cause irreversible mental retardation.
- Newborn screening for CH is vital for early intervention and normal cognitive development.
- While widespread, newborn screening for CH is not yet universal globally.
Purpose of the Study:
- To review current practices and outcomes in managing congenital hypothyroidism.
- To emphasize the importance of early diagnosis and appropriate thyroid hormone replacement therapy.
- To discuss ongoing research and controversies in CH management.
Main Methods:
- Review of existing literature on congenital hypothyroidism screening and treatment.
- Analysis of therapeutic goals and recommended levothyroxine dosages.
- Discussion of developmental outcomes in treated individuals.
Main Results:
- Early screening and treatment (within 2 weeks) normalize cognitive development.
- Modern, aggressive thyroid hormone therapy regimens improve outcomes.
- Improved developmental outcomes are observed in adults treated for CH.
Conclusions:
- Timely intervention in congenital hypothyroidism ensures optimal neurodevelopmental prognosis.
- Ongoing research aims to refine therapy for transient, mild, or preterm CH cases.
- Clinical judgment remains essential, even with normal newborn screening, as hypothyroidism can be acquired.
Abstract:
Unrecognized congenital hypothyroidism leads to mental retardation. Newborn screening and thyroid therapy started within 2 weeks of age can normalize cognitive development. The primary thyroid-stimulating hormone screening has become standard in many parts of the world. However, newborn thyroid screening is not yet universal in some countries. Initial dosage of 10 to 15 microg/kg levothyroxine is recommended. The goals of thyroid hormone therapy should be to maintain frequent evaluations of total thyroxine or free thyroxine in the upper half of the reference range during the first 3 years of life and to normalize the serum thyroid-stimulating hormone concentration to ensure optimal thyroid hormone dosage and compliance. Improvements in screening and therapy have led to improved developmental outcomes in adults with congenital hypothyroidism who are now in their 20s and 30s. Thyroid hormone regimens used today are more aggressive in targeting early correction of thyroid-stimulating hormone than were those used 20 or even 10 years ago. Thus, newborn infants with congenital hypothyroidism today may have an even better intellectual and neurologic prognosis. Efforts are ongoing to establish the optimal therapy that leads to maximum potential for normal development for infants with congenital hypothyroidism. Remaining controversy centers on infants whose abnormality in neonatal thyroid function is transient or mild and on optimal care of very low birth weight or preterm infants. Of note, thyroid-stimulating hormone is not elevated in central hypothyroidism. An algorithm is proposed for diagnosis and management. Physicians must not relinquish their clinical judgment and experience in the face of normal newborn thyroid test results. Hypothyroidism can be acquired after the newborn screening. When clinical symptoms and signs suggest hypothyroidism, regardless of newborn screening results, serum free thyroxine and thyroid-stimulating hormone determinations should be performed.
